Nadir Ciftci and Kudus Oyenuga brought the Under20s their first goals and win of the season at Firhill tonight.
But the marksmen weren't the only ones to catch the eye in a fine all round performance by the visitors with Ryan Gauld particularly outstanding.
Only a brilliant finger-tip save by home keeper Marc Walters prevented United taking a second minute lead.
He was at full stretch to push the returning Mark Millar's first time 25-yarder round the post.
The Tangerines continued to dominate and five minutes later Ryan Gauld blocked a Walters clearance to set up Nadir Ciftci, but a Thistle defender blocked his netbound effort.
And just after the quarter of an hour mark, Gauld was again the architect, this time for Kudus Oyenuga, but the keeper at close quarters blocked his effort.
The goal United had been threatened finally arrived after 19 minutes courtesy of Ciftci. Gauld slipped in Ciftci who calmly rounded keeper and scored.
Rarely seen before then Thistle started to threaten.
Midway through the half, Dale Keenan forced a fine save from Joe McGovern. And twice before the break, Ross Meechan and Darren Brownlie struck the bar.
However, United started the second half just as they had done in the first by almost scoring. Once more Gauld was the creator. He played in Scott Fraser, but Walters just managed to push his effort past the far post.
The visitors continued to keep the Jags keeper busy and Oyenuga was next to test him with a low drive that he kept out with his feet.
However, on 57 minutes Ciftci struck again and his venomous strike from 30-yards arrowed its way into the top left-hand corner, giving the keeper no chance.
And to round off a highly satisfactory evening, Oyenuga added the third with a shot from just outside the box that Walters ought to have kept out with a little under 20 minutes remaining.
Dundee United: McGovern, Gilmour, S Smith, M Millar, J Souttar, Petrie, Connolly, Fraser, Oyenuga (Tumilty 81), Gauld (Montgomery 67), Ciftci (M Russell 67)
Substitutes not used: Anderson, H Souttar,